Disclaimer: Vorzüge sent me DUO II samples for review at Headfonia. Finally, I have shot two advertising images for Vorzüge. DUO II goes for 799$ USD. You can find out all about it here: VorzAMPDuo II ™.

Until this moment, until 2017 January 12 around 9PM, want to know what my most recommended portable battery-powered headphone amplifier was? I’ll tell you. It was Vorzüge’s PURE II (both versions). I can get it to eat up an overdriven Chord Mojo signal of 122dB and spit back around 120dB. At stable volumes, it measures between 118-119dB. It is an amazing amp whose load stability, signal to noise ratio, THD, IMD, and dynamic range are matched by almost no one.

The only area it suffers - and that only mildly - is stereo separation. That hovers around 80dB. Amps and sources that return super-low stereo crosstalk numbers are often said to sound flat, or enengaging . Some people swear they cast small stages. Whatever the subjective opinion about stereo crosstalk and its affects on audio, it is PURE II’s single measurable weakness. And yet it is the best-sounding portable amp I’ve heard.

DUO II is right up there with it in almost all measurements. But it adds a brilliant EQ. Background noise is just as low. At low gain, hiss is almost non-existent. Whatever I said in my reviews of PURE II and PURE II+ apply equally to DUO II. Unfortunately that means that DUO II inherited the still-mad bright ON/OFF lamp.

Whatever the case, it is the most versatile battery-powered portable headphone amp I’ve tried. No, it’s not as powerful as MyST’s PortAMP II (nothing really is). Not, it’s not as warm as ALO’s CDM. But, having now adopted PURE II’s brilliant gain stage, it is perfectly suitable to sensitive earphones. And, with up to 12dB of EQ’d bass gains, it breaths new bump into bass-shy earphones. Or, if 12dB is too much, you can add just 3dB.

The original DUO was rad, just not across the board. That is, its gain system was too aggressive. Sensitive earphones would blast at the slightest nudge of the attenuator. That’s been fixed. And, without exception, DUO II performs even better. Bettering any Vorzüge amp is difficult. Bettering across the board is ridiculous.